mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-09 07:51:16 -04:00
27d1a4dbe1
The alert functionality is an out of range indicator and can be used as an early indicator of an out of bounds conversion result. ALERT_LOW_THRESHOLD and ALERT_HIGH_THRESHOLD registers are common to all channels. When using 1 SDO line (only mode supported by the driver right now), i.e data outputs only on SDOA, SDOB (or SDOD for 4 channels variants) is used as an alert pin. The alert pin is updated at the end of the conversion (set to low if an alert occurs) and is cleared on a falling edge of CS. The ALERT register contains information about the exact alert status: channel and direction. ALERT register can be accessed using debugfs if enabled. User can set high/low thresholds and enable alert detection using the regular iio events attributes: events/in_thresh_falling_value events/in_thresh_rising_value events/thresh_either_en In most use cases, user will hardwire the alert pin to trigger a shutdown. In theory, we could generate userspace IIO events for alerts, but this is not implemented yet for several reasons [1]. This can be implemented later if a real use case actually requires it. Signed-off-by: Julien Stephan <jstephan@baylibre.com> [1] https://lore.kernel.org/all/4be16272-5197-4fa1-918c-c4cdfcaee02e@baylibre.com/ Reviewed-by: David Lechner <dlechner@baylibre.com> Link: https://patch.msgid.link/20250108-ad7380-add-alert-support-v4-4-1751802471ba@baylibre.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.